One of the U.S.-Ukraine diplomats has a lengthy history as a Republican donor, while another performed lobbying work for foreign clients and a major defense company.

(By  Karl Evers-Hillstrom and Yue Stella Yu, The Center for Responsive Politics) A series of text messages between U.S. diplomats released Thursday night reveals an apparent effort to pressure Ukraine into performing an investigation that could prove harmful to President Donald Trump’s potential 2020 opponent.

One of the diplomats involved has a lengthy history as a Republican donor, while another performed lobbying work for foreign clients and a major defense company.

In the exchanges, acting ambassador to Ukraine William Taylor asked Gordon Sondland, ambassador to the European Union, if U.S. security assistance to Ukraine was dependent on “investigations.” Sondland responded, “Call me.”

One week later, Taylor texted Sondland: “As I said on the phone, I think it’s crazy to withhold security assistance for help with a political campaign.” Sondland responded by texting Taylor he was “incorrect,” then said the diplomats should stop communicating by text.

As House Democrats pursue an impeachment inquiry against the president, they say the messages reveal that Trump demanded Ukraine investigate Democratic presidential contender Joe Biden and his son in exchange for military assistance that was being withheld by the administration. State Department officials said the texts don’t tell the whole story.

Also involved in the exchanges was Kurt Volker, former U.S. special envoy to Ukraine who resigned a week ago after being mentioned in the explosive whistleblower complaint.

While Taylor is a career diplomat with no record of political contributions in OpenSecrets’ database, Volker and Sondland were GOP donors before taking their new jobs in government, though one gives far more than the other.

Sondland, who was considered an unlikely choice for his position, is a major Republican donor and bundler. He has given more than $446,000 to federal candidates and groups, 94 percent of which went to Republican causes. In the run-up to the 2016 election, Sondland denied he was sponsoring a 2016 fundraiser event in Seattle for the Trump campaign and said he did not agree with Trump’s values.

But Sondland was listed as one of Trump’s bundlers in 2016. And after Trump won, he funneled $1 million into Trump’s inaugural committee through four different LLCs, OpenSecrets reported.

Political donors and bundlers are often selected to ambassador and diplomat positions, with the cushiest jobs going to the most generous givers.

The White House tapped Sondland as the U.S. ambassador to the EU in March 2018. He was confirmed by the Senate two months later. One of Sondland’s biggest supporters in the upper chamber, Sen. Thom Tillis (R-N.C.), received a total of $17,900 since 2016 from the to-be diplomat between his campaign and leadership PAC. Katherine Durant, Sondland’s wife, is a big donor herself, giving nearly $294,000 to federal candidates and groups and $57,900 to a Tillis-related joint fundraising committee in May.

Also assisting Sondland in the nominations process was former Sen. Jon Kyl (R-Ariz.), a perpetual revolver. Sondland reporting paying $60,000 to Kyl and two other Covington & Burling lobbyists to help him prepare for the confirmation process.

Sondland’s political contributions date back to the 1980s when he was still an investor. He started his real estate investment company, Dunson Equities Corporation, in 1989, which was dissolved in 2013. He’s now the director of private equity firm Aspen Companies and the CEO of Provenance Hotels.

Since 2007, the Portland, Oregon businessman has personally given the Republican National Committee $218,300 and the National Republican Senatorial Committee $68,400. Before bundling for Trump, Sondland gave more than $23,000 to Jeb Bush’s Right to Rise USA super PAC. He also gave $5,400 to Sen. Rand Paul (R-Ky.) and $2,700 to Sen. Rob Portman (R-Ohio), who reportedly pushed Trump to give military aid to Ukraine. CNN revealed this week that Portman, along with then-Vice President Biden and other Republican senators, supported U.S. efforts to pressure Ukraine to fire its chief prosecutor in 2016.

Appointed to his post in 2017, Volker is less prolific as a donor, giving just $3,000 to federal candidates and groups, including $1,000 to then-presidential contender Mitt Romney in 2012 and $1,000 to Bush’s Right to Rise. Volker was a registered lobbyist for BGR Group from 2011 to 2012, where he lobbied for former Georgian Prime Minister Bidzina Ivanishvili and defense giant Raytheon, among others. Volker came under scrutiny for promoting weapons manufactured by Raytheon while in government.

Marie Yovanovitch, former ambassador to Ukraine, doesn’t have a record of federal political contributions.  Trump personally ordered Yovanovitch to be removed from her position after complaints from Rudy Giuliani that she was blocking investigations into Biden, the Wall Street Journal reported. Yovanovitch is set to testify before Congress on Oct. 11.

Another State Department official House Democrats want to hear from is Ulrich Brechbuhl. The State Department counselor was appointed by Secretary of State Mike Pompeo in 2018 after giving $12,200 to Pompeo’s congressional campaigns since 2009.

Trump doubled down Thursday when he told reporters that Ukraine, as well as China, should look into the Bidens. Ukraine has said the Biden-linked case will be reviewed.

Most campaign finance experts agree that soliciting a criminal investigation into a potential political opponent, at a bare minimum, likely goes against campaign finance law. Campaigns are barred from accepting or soliciting a “thing of value” from foreign nationals or governments in connection with an election. The Department of Justice, led by Bill Barr, said Trump’s July 25 call with Ukrainian President Volodymyr Zelensky did not constitute a campaign finance violation.

The Federal Election Commission, the agency tasked with enforcing campaign finance law, cannot do its job as it is down to three commissioners out of a possible six. Only Trump and the Senate can change that.

Researchers Doug Weber and Alex Baumgart contributed to this report.